Jesse Levinson, the company’s other co-founder and current chief technology officer, will be promoted to president, said a person familiar with the decision who asked not to be identified because the discussions are private. The person declined to offer an explanation for the move. Carl Bass, the former CEO of Autodesk and a Zoox board member, was named executive chairman for the company.

In an emotional missive on Twitter, Kentley-Klay criticized the board for its decision. “Rather than working through the issues in an epic startup for the win, the board chose the path of fear,” he wrote, charging that the directors were “optimizing for a little money in hand at the expense of profound progress.”

Zoox stood out in the crowded field of self-driving newcomers and corporate titans for its outsized ambition and financial backing. The 4-year-old company, which has raised about $800 million to date, including $500 million in July, aims to create a fully driverless vehicle ready for the road by 2020. Bloomberg Businessweek recently profiled the young company’s rapid ascendance in Silicon Valley, which was driven largely by the unorthodox entrepreneurial zeal of Kentley-Klay, an Australian native with no prior automotive experience.

“We are a startup pitted against the biggest companies on the planet,” Kentley-Klay told Businessweek. “But we believe deeply that what we’re building is the right thing. Creativity and technical elegance will win here.”

Before starting Zoox, Kentley-Klay was offered a job with Google’s self-driving project, now called Waymo. He turned it down, and has touted Zoox’s strategy of building its own vehicles for full autonomy as wiser than the standard approach of retrofitting existing cars that Alphabet Inc.’s Waymo and others are taking.

The Zoox board, which includes Levinson, voted to oust Kentley-Klay, said the person familiar with the situation. A spokesperson for the company declined to comment.